1.9 THz indirect injection Al0.175Ga0.825As/GaAs quantum cascade laser operating at extreme higher temperature

Terahertz quantum cascade lasers (THz QCLs) are a promising semiconductor THz source to realize the expected widely compact size THz applications. Currently limitation of THz QCLs is the limited maximum operation temperature (T_max) and the extension of the operation frequency. Here we propose one Al_0.175Ga_0.825As/GaAs indirect injection design QCLs operated near 1.9 THz with 160 K. Indirect scattering assisted selective injection design with higher Al composition barrier expected to approach low frequency with high temperature operation.